The present disclosure relates to a method of manufacturing a semiconductor laser element.
In the related art, a semiconductor laser element that emits laser light from a facet thereof is manufactured by formation of a dielectric film, which is formed of a dielectric oxide, such as silicon oxide or aluminum oxide, on the facet of a semiconductor light emission element thereof, for adjustment of reflectivity thereof and the like. In this case, a technique for cleaning has been disclosed, in which impurities present on the facet are removed before the dielectric film is formed thereon, in order to keep generation of Catastrophic Optical Damage (COD) less on the facet and improve reliability of the semiconductor laser element. For example, in Japanese Laid-open Patent Publication No. 2000-164969 and Japanese Laid-open Patent Publication No. 2008-166852, by use of an Electron Cyclotron Resonance (ECR) sputtering device, first, cleaning is carried out by: generating plasma in a state where no high frequency power or bias is applied to a silicon target; and irradiating plasma to a facet to be cleaned. Thereafter, by use of the same ECR sputtering device, the silicon target is sputtered and a dielectric film made of silicon oxide is formed on the cleaned facet by generating plasma in a state where high frequency power or bias voltage is applied to the silicon target.